Wireless Digital Rights Management (DRM) technology provides a technical solution based on remote certification, digital watermark (finger print), algorithm encryption technologies for the protection of digital contents like text, image, music, or media files, which are broadcasted online over network.
Effective DRM solution allows a digital content provider of network to control access authorization for browsing and reading digital contents, no matter whether the contents are text, music, image or other media files. DRM solution ensures that only legal authorized users can own corresponding rights. Each authorized user, after paying for certain charges, will get an exclusively corresponding user ID and password as well, and will be given a granted terminal media player that is corresponding with the encryption algorithm.
In order to trace the piracy, in the traditional DRM system, in response to the digital content request from the users, i.e. digital format media files like text, music, image, the Piracy Tracing Method uses digital fingerprint technology to send a copy of the requested contents to the requesting user. Wherein said copy is embedded with a fingerprint corresponding to user information and forms into a different version of the same contents. To avoid reproducing the unauthorized copy and its releasing, the digital content provider would embed IDs or serial number of different users as various fingerprints in legal copy of the contents (this can be realized with watermark technology). When piracy occurs, the version and source of piracy can be identified by restoring the fingerprint from the pirated copy and therefore the user that is related to said fingerprint can be found out so as to identify the pirate(s). The procedure for how to discover a piracy would be not discussed in this application.
Unlike traditional DRM system in which the protected contents are distributed from a provider to end-users, the wireless DRM system has its unique features, i.e. the content providers wish that their digital contents protected by encryption could be broadcasted in the form of a super-distribute. The content providers hope that more legal users can obtain various digital media contents they provided. To be more specific, after the content providers have provided their digital contents to a group of users (hereinafter called the first level users), the content providers also hope that the first level users can redistribute the protected contents they received to other users (hereinafter called the second level users) in a legitimate way. Therefore the digital contents can be distributed more extensively. When the first level users redistribute the content to the second level users, before receiving the contents, the second level users also need to obtain authorization and become legal users to be able to use the contents normally. Similarly, the second level users can further redistribute the contents to third level users. Therefore, the content providers can make a profit by charging the legal users from multiple redistributions of their contents. Under the circumstance of the redistribution (or Super-Distribution Mode), the users are encouraged to further super-distribution the protected contents they received in a legitimate way. In the current wireless DRM system, the copyright protection of the digital contents relies on the publishing by the users (namely the legal right objects) who receive/use the protected contents. However, this super-distribution mode makes it impossible for the traditional piracy tracing method to effectively spot the users who disclose the protected contents. To be more specific, if the pirated contents (disclosed contents) are disclosed by the first level users, the current DRM technology, by restoring the fingerprint from the pirated contents to determine the source of the piracy, could find out the users related to the fingerprint mentioned and identify the pirates (leaking point). However, after multiple redistributions through super-distribution, if the pirated contents are disclosed by the second level users or the third level users and even the further lower level users, the current DRM technology can only locate the pirates in the first level users because the redistributed contents only contains the fingerprints related to the first level users. When the pirates appear in the second level users or in the third level users, it is impossible to specifically identify the leaking point of the digital contents in the wireless DRM system.
Robust DRM system should be able to endure hacker's attack. This means the system should be able to uphold the attack from hackers and identify the hackers. The latter is the so-called piracy tracing. Only through effective tracing can the operator take measures either to delete the hacker's account or sue the hacker. But the current technology DRM System is unable to effectively, accurately identify the pirates or hackers. Therefore, it is unable to prevent from piracy effectively.